Flow-meter for marine purposes.



J. WILKINSON.

FLOW METER FOR MARINE PURPOSES.

APPLICATION FILED IUNE I4. 1913.

Patented Feb. 1, 1916.

hm/JUNE ARN, M.

Inventor": James WilKi id \A/"ltnesses: 2L i ZQ.

nsor),

HisJfiator-n e3.

UNITED STATES PATENT cur os.

JAMES WILFINSON,

OF SCHENECTADY, NEW YORK, ASSIG-NOR TO GENERAL ELECTRIC COMPANY, A'CORPORATION OF NEW YORK.

FLOW-METER FOR MARINE PURPOSES.

Specification of Letters Patent.

Fatented Feb. 1, 1916.

Application filed June 14, 1913. Serial No. 773,60

To all whom it may concern:

Be it known that I, JAMES WILKINSON, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have-invented certain new and useful Improvements in Flow-Meters for Marine Purposes, of which the following is a specification.

This invention relates to instruments for indicating the rate of ii ow of a fluid through a conduit, and is especially designed for marine service, the object being to secure accurate readings in spite of the inclination of the meter due to the rolling and pitching of the vessel. In one of the ordinary types of flow meter, a pressure difference device, such as a Venturi or Pitot tube or the like, is inserted in the conduit through which flows the fluid to be metered. The high or leading pressure region of this device is connected with one leg of a U-shaped tube or equivalent structure, and the low or trailing pressure region of said device connects with the otherleg of said tube, in which is a mass of mercury, movable to and fro by the variations in pressure. My invention has special reference to this type of indi cating instrument. The height of the mercury column in the trailing leg of the meter is due to the difl'erence between the leading and trailing pressures. The column will rise and fall in accordance with the fluctuations in pressure due to variations in fluid flow. If the tube is inclined, the mercury will flow up along it,.so as to maintain the same vertical difference in head in the leading and trailing legs. of the meter. But this action of the mercury l"6S false readings, because the upper end of the column advances to higher graduation marks when the tube is'inclined, although there may have been no increase in flow. The purpose of my invention is to correct this error, and enable the instrument to give true readings even when inclined. I accomplish this by automatically lowering the level of the mercury surfaces exposed to the leading and trailing pressures, whenever the tube is tilted. In this way, the vertical head of the mercury column is maintained when the tube tilts,

but the entire column is lowered so as to keep the upper end of said column at the same graduation mark so long as there is no change in fluid flow. Moreover, when the tubeis vertical, a predetermined diil'erence in fluid flow, producing a given change in the leading and trailing pressures, causes the top of the column ofmercury to shift a given space in the tube, between two of the graduation marks on the scale. But when the tube is inclined, the vertical height between any-two graduation marks becomes less, so that for a given change in fluid. flow the top of the mercury column would not coincide with the same marl: as when the tube is vertical. My invention provides also for this contingency by automatically decreasing the area of the surface of mercury exposed to the leading pressure, whenever the tube is tilted; the result of which is that for a given increase in the leading pressure a decreased quantity of mercury is forced into the trailing column; This reduced quantity will not give so high a reading as would be the case if the leading surface area had not ldeen reduced when the tube was tilted. By this change in the ratio of the leading and trailing surface areas I thus effect a correction of what would otherwise have been too high a reading of the gauge. '1 effect this automatic change in ratio of areas by the design of the receptacle for the mercury at the base of the column, said receptacle forming the chamber or leg of the U-shaped tube in. which the leading pressure exerts its action. When the instrument is vertical, the area of the mercury in said chamber is greatest, but as the instrument. tilts away from the vertical, this area decreases and its surface lowers. The shape of the chamher I prefer is circular in horizontal section and elliptical in vertical section; in other words, an oblate ellipsoid, with its major diameter horizontal. hen such a chamber contains mercury the arear of the surface of said mercury is at its maximum when the major of said chamber is horizontal. As the chamber is inclined, this area decreases until it reaches a minimum when the minor axis becomes horizontal.

In the accompanying drawing, Figure 1 is a. vertical section, partly in elevation of a fluid flow meter embodying my invention, the index standing at zero; Fig. 's a similar section of the lower oortion of the'instrument, showing the position of the index when measuring a flow of 30 pounds ofsteam per hour; Fig. 3 is a view similar to the graduations.

Fig. 2, showing the instrumenttilted with the index still standing at the 30 pound mark; and Fig. 4 shows how the meter is connectedto a steam or other conduit.

lhe fluid to be measured flows through a. conduit l'in the direction of the arrow. A differential pressure device is inserted in the conduit, pnpferably a.nozzle plug 2 having a long leading-face 3 and a long trailing face 4 to obtain the average condition of flow and communicating respectively by.

pipes 5, 6 with the leading and trailing chambers 7, 8 of the meter. The chamber 7 has the shape of an oblate ellipsoid and is formed in the base 9 of the meter. Rising from saidbase is a tubular stem 10 whose lower end has a tubular extension 11 depending into the chamber '7. In the bottom of said chamber is a well 12 in line with said extension and receiving a tubular plug 13 screwed into the end of said'extension.

In the front of the stem 10 is a longitu dinal slot surrounded by a flattened surface provided with graduation marks Through the slot can be seen alglass tube 14: inclosed in the stem and provided with packing gaskets 15 clamped by a gland l6 and a slotted spacing sleeve 16. Above the tube is the trailing chamber 8 closedv by, a packed cap 17. AYbody of inercury, 18"is contained-in the chamber 7,] 'n d resting upon that portion which lies in the tubulah extension 11 is a small float 19. Aslender rod 20 is at-.

tached to said float and extends up into the glass tube l t passing through a guiding construetionQl in' the bore 2-2 of the stem just below. thetribe. 'Bythe side ofthe slot .in the stem are graduations 23 indicating pre erably pounds of steam per hour, and

= on the rod'2O is .an ndexer whichfcotiperates with said gi'aduations The instrument 'may be direct'radingior a constant may be employed. .i/Vhjeh; no. fluid. through the conduit the static pr same in both of'thebhzimbers 7 a S, and the mercury 18 stands at the same ievel in the chamber 7 and the bore of the stand ard 10, as shownin Fig. 1. But when a How of fluid occurs, the pressure nozzle plug sets" up differential. pressures in the chambers 'Z and 8, SO that'the mercury rises in. the standard and the float 19 pushes up the index 24: to give the proper reading of When the meter is inclined, the surface of the mercury assumes a position more or less-oblique tothe major 112.1; of chamber 7, indicated in Fig. 3. in this position its area is decreased with every departure of the chamber from a lmrixontai position, owing to'its ellipsoidal torm..so that the ratio between the areas in he chamber 7 and the bore 2"). is similarly dramas-ed. The level of the. mercury also falls below what it was when the chamber was horizontal. In order that this drop s the shall be just sufficient to-compensate. for the lengthening clue to the inclination of the tube, the chamber mustbe long and shallow, and less than half full of mercury. This shape will also decrease the ratio between" It is evident that my =me'terwi1l operate equally well with other well known-devices for establishing 'regions'ofdifferential pressure, such .as a Venturi tube, a pair of Pitot funnels, a choking washer or a spindleshaped body-in the conduit, and the like.

In accordance with the provisions of the patent statutes, I have described the principle of operation of my invention, together withthe apparatus which I now. consider to represent the best embodiment thereof; but

I desire to have it understood that the ap:

paratus shown is only illustrative, and that the invention. can be carried out by other means.-

Vihat I claim asnew and desire to secure by Letters Patent of the United States, 'is:-

l; A fluid flow meter having' a fluid containing tube provided. with leading; and

trailing legs, "a portion-ofthe. leading leg being of such a configuration as to decrease automatically the area of the exposed surdeparture of said portion from a horizontal position.

2 A fluid flow meter having a fluid containing tube which has a mercury chamber for the leading pressure whose shape is that of an oblate ellipsoid.

3. A steam flowmeter having a base containing a chamber, a body of fiuid in said chamber, a tubular stem rising from the base and-having an extension prgectmg down into. said find, a glazed longitudinal slot in said: stem, a"flatsurface'o n said stem ad acentto. said slot and provide with graduationmarks, a'tioat in said stem having'a rod, an index on the upper end of said rod observable throughsaid' slot, and means for connectin said chamber and the upper end of said stem-respectively with the high and low pressure regions of a pressure difference device. I

4. The combination with a conduit for face of the mercury in said leg' with every fluids, of a. pressure-difference device there on, a base containing a chamber connected.

with the. high-pressure region of said device, a longitudinallyslotted tubular stem rising from said and havrng an extension de- 5 the two chambers and a igfmxms pending into said chamber, a chamber at the top of said stem connected with the ow pressure region of said. pwssm'rc l'iiifmexure device, a glass tube in said stem ernn'mer at in time i having a rod Whose upper and is 017- through said slot. 

